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leather shapes leather shapes

KINGSMERE CRAFTS

HAND-CRAFTED LEATHER GOODS

Some things to know about leather

Today's leather industry is scientifically based. Continuous research is carried out to ensure improvement in the product. The latest technology is used to meet modern day demands. With few exceptions hides and skins are by-products. Animals are reared for meat, milk and wool, not for the value of their skins. Consequently, the tanner is not able to control his supply of raw hides. 

Heinen Lederfabrik - Beamhouse/Tanning


Leather was a vital Victorian commodity and tanners were highly skilled workers, but they were forced to live on the fringes of society because of the noxious smells that went with the job. Raw hides were dipped in a sickly, sweet-smelling, lime solution for a week, before the tanner scraped off the rotted flesh and hair. They were then soaked in "bate" –a warm, steaming gruel, made using water and dog faeces, which removed the lime, softened the hides and stunk the yard out something terrible! Over the next twelve months, the hides would be soaked in various tanning solutions before being meticulously rinsed and the drying out process began. The work was dull, strenuous and very, very smelly. Little wonder that tanners usually married other tanners!

Hides are traded as a commodity all over the world, on open markets, and in competition with other tanners. Thus, when demand is heavy, prices soar. Even minor variations in economies and currencies can cause major fluctuations in raw hide prices. The availability of cattle hides for leather is simply dependent upon consumer demand for beef. Today, worldwide, at least half the leather produced goes into footwear, and around a quarter for clothing. About 15% goes into upholstery and the rest into small leathergoods. 

Because of its durability and comfort, leather, throughout its history, has been used for seating purposes in domestic furniture and transportation. Early leathers were made from cowhide, calfskin, pigskin, deerskin, and goatskin. The hides and skins coming from animals either hunted or farmed for food purposes. 

Presently, the trend is for most upholstery to be made from bovine material (that is to say cattle hides) as they are readily available and best lends itself to the modern demands of designer, producer and consumer. Far from waning in popularity, leather continues to be the material of choice for many people, not just for household furniture but for automotive, aviation and marine applications too.

If in the first instance the quality of the hide or skin is good, the less treatment is needed. With a first quality hide or skin the full natural grain is kept, indeed, exposed. The fat wrinkles, natural markings caused by barbed wire and so on, should be seen, and the "feel" should be of suppleness.

The term "top grain" is a bit of a misnomer. Surprisingly it means the opposite of what you might suppose. "Top grain" is generally used when the grain is not genuine, in fact, when the original grain has been removed and an imitation grain has been embossed into the leather. The correct description for the original grain is "full grain" or "full top grain".

Calfskins, as is to be expected, are finer than the hides of older animals, but are equally durable and abrasion resistant due to the fibre structure being denser, tighter and stronger, than that of cowhide. So in descending order of quality we have calfskin, first grade cowhide and suede, selected cowhide, third-grade cowhide.

vegtan tooling

Skirtside

Double shoulder

Veg-tan tooling


All leather is treated with anti-mould agents such as paranitrophenol or sodium pentachlorophenate, during the tanning process. These agents are rotated approximately every six months to avoid immunisation. These products are also bactericides.

Changing hides and skins into leather involves three stages, pre-tanning, tanning and finishing. Anyway, after tanning, everything else is part of the finishing process. By the finishing process is meant dyeing, pressing, rolling, plasticising, lacquering, antiquing, waxing, buffing, embossing, glazing, waterproofing, stain-proofing, flame-proofing and so on. Full grain leather stained with aniline vegetable dyes does not have any natural markings concealed, they show through. Upholstery leathers do get treated with pigments however, to even out the colour.

Sheepskin skiver

Many finishes are applied for reasons other than altering the surface of the leather. With natural, unpigmented leather, the leather is able to breathe, so it can absorb moisture, receive nourishment, and remain supple and soft. If it has been plasticised, as in most car upholstery leathers, it cannot, and it will eventually become stiff and liable to cracking.

The natural characteristics of leather

Real leather is a natural product. It breathes, is warm and has individual characteristics that make each hide unique. Leather will always bear the marks of its natural origin and these characteristics can show as healed scars, growth marks, areas of differing fibre density and hair pore structure. These hallmarks in no way detract from the wearing qualities of the leather. They are signs discerning owners cherish when buying leather. With the passing of time and use, it develops a patina that enhances its beauty.

1 Growth Marks and Veins - These are an indication of the age of the animal and in that respect is similar to the graining on a piece of timber. They range from often quite pronounced marks in the neck area to subtle bands across the hide perpendicular to the backbone. Heavy growth marks are often placed on the outside backs of seating.

2 Scars - These form usually as a result of barbed wire damage or by the horns of other cattle. In their healed form the new skin is as strong as the remainder of the hide but unhealed damage should be avoided as tension on these parts may cause the leather to split or burst.

3 Grain Variation - The fibre texture varies greatly from being loose in the belly and flank areas to being relatively tight across the backbone. The looser areas consequently have more stretch.
The variation in hair pore structure is particularly noticeable in untextured leathers where clusters of open pores can sometimes be seen.

4 Shade Variation - No two hides are alike and due to the varying grain structure mentioned above the dyes and finishes penetrate to differing degrees in different parts of the hide to give an attractive variation. Whilst every attempt is made to achieve uniformity this is not always possible and sometimes not desirable.

British leather:- In the British home supply there are three chief breeds: (1) Shorthorns (Scotch breed), (2) Herefords (Midland breed), (3) Lowland, or Dutch class. From a tanners standpoint, the shorthorns are the best hides procurable. The cattle are exposed to a variable climate in the mountainous districts of Scotland, and nature, adapting herself to circumstances, provides them with a thicker and more compact hide; they are well grown, have short necks and small heads. The Hereford class are probably the best English hide; they likewise have small heads and horns, and produce good solid sole leather. The Lowland hides come chiefly from Suffolk, Kent and Surrey; the animals have long legs, long necks and big heads. The hides are usually thin and "spready". The hides of the animals killed for the Christmas season are poor. The animals being stall-fed for the beef, the hides become distended, thin and surcharged with fat, which renders them unsuitable for first-class work.

Cleaning of finished leather

Cleaning:- Cleaning is perhaps something that is given too much emphasis. Leather furniture in a normal domestic environment should require little attention and any cleaning should be done only when necessary. It is not essential to the life of leather that it should be cleaned regularly, but at the same time an accumulation of dirt and grease over a period of time is undesirable and obviously, the longer it is left the more difficult it will be to remove. Dirt is abrasive and over a period of time in extreme circumstances will cause the removal of the protective coating. Regular cleaning can be done simply by using a damp cloth, taking care not to soak the leather. 

It should be noted that full grain aniline leather or russet leathers cannot be cleaned with water or soap solution. Any attempt to do so could result in the leather being irreparably damaged.

Cleaning objects made from skin products cannot be done safely without knowing what process has been used in their preparation. Sometimes the application can provide clues. Parchments, drum heads, and coverings of wooden boxes are made from raw skin that has had no tanning or other chemical treatment. Old items of Aboriginal clothing are likely to be semi-tanned (a process similar to fat liquoring, but not as effective) while newer items, regardless of source, are likely to be chrome tanned. Handbags, bookbindings, and other items that do not need high water resistance might be made from vegetable-tanned leathers. Items such as shoes and clothing tend to be made of leathers that are durable and water-resistant. If made in the 21st century, the leather is likely to be mineral-tanned. The resistance of these items to water, and thus the potential for effective cleaning, follows the order indicated below:
  1. rawhide and parchment - most sensitive
  2. alum tawing
  3. semi-tanned skin
  4. vegetable-tanned leather
  5. mineral-tanned leather - least sensitive

Obviously, with the wide range of skin products, and the corresponding wide range of applications, it is dangerous to generalize. When in doubt, seek professional advice.

  • For all semi-tanned skins and those that have soft, sueded surfaces, use a soft brush and vacuum cleaner. Brush towards the nozzle of the vacuum cleaner. Place a piece of gauze window screening over sensitive areas and vacuum through it. A stiffer brush, such as an artist's hog bristle, can be used on resistant areas, but be very cautious because this might change the surface appearance.

  • Rawhides and parchments can be cleaned with the powdered eraser used by draughtsmen or a gum eraser. These materials should be applied very carefully because a vigorous application can cause over-cleaning. If there is any writing, painting or other design on the skin, do not clean. Get advice from a conservator.

  • Vegetable-tanned leathers can be cleaned by damp swabbing. Make sure that the leather is in sound, stable condition. Any sign of cracking or a powdery surface should be a warning that deterioration is taking place. If the leather is in good condition, use a soft cloth moistened with water to which has been added a few drops of liquid detergent. Rub gently and dry afterwards with another soft cloth, thus making sure that moisture is not left on the surface. The same technique can be used for mineral-tanned leathers that are very resistant to water.

It is very common to apply leather dressings of various kinds to keep objects soft and flexible while in use. These materials are not generally recommended for heirlooms or heritage objects because their conditions of use and handling are different. Leather objects that are used every day, such as saddlery and furniture coverings, do benefit from treatment, but objects that lie unused or stored away tend to get sticky and attract dust and insects. Professional advice should be sought before applying any such treatment.

Handling:- Flexible leather objects in good overall condition can be handled without problems. If objects are not on display, it is advisable to keep them wrapped in acid-free tissue paper and stored in such a way that they are not creased or distorted. Shoes and bags should be stuffed lightly with acid-free tissue to help maintain their shape, and light garments should be hung on padded hangers. Heavy leather garments are best stored flat to avoid distortion due to gravity. Flat skin or leather pieces should be wrapped in tissue and kept in a flat, rigid binder or folder to prevent distortion.

Repair:- Repair of historic leather and skin objects is usually needed when items are badly deteriorated. Before repair is done, deterioration needs to be dealt with. In most cases, such repairs are a job for the specialist. If in doubt, consult a conservator.


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leather shapes leather shapes